<a class="button small hollow" ng-click="start()">
    {{text}}
    <img height="16" width="16" src="./assets/img/spinner.gif" ng-show="loading" />
    <img height="16" width="16" src="./assets/img/ok.svg" ng-show="success" />
    <img height="16" width="16" src="./assets/img/error.svg" ng-show="error" />
</a>